Evaluation of immobilized lipases on poly-hydroxybutyrate beads to catalyze biodiesel synthesis

Abstract

Five microbial lipase preparations from several sources were immobilized by hydrophobic adsorption on small or large poly-hydroxybutyrate (PHB) beads and the effect of the support particle size on the biocatalyst activity was assessed in the hydrolysis of olive oil, esterification of butyric acid with butanol and transesterification of babassu oil (Orbignya sp.) with ethanol. The catalytic activity of the immobilized lipases in both olive oil hydrolysis and biodiesel synthesis was influenced by the particle size of PHB and lipase source. In the esterification reaction such influence was not observed. Geobacillus thermocatenulatus lipase (BTL2) was considered to be inadequate to catalyze biodiesel synthesis, but displayed high esterification activity. Butyl butyrate synthesis catalyzed by BTL2 immobilized on small PHB beads gave the highest yield (≈90 mmol L(-1)). In biodiesel synthesis, the catalytic activity of the immobilized lipases was significantly increased in comparison to the free lipases. Full conversion of babassu oil into ethyl esters was achieved at 72 h in the presence of Pseudozyma antarctica type B (CALB), Thermomyces lanuginosus lipase (Lipex(®) 100 L) immobilized on either small or large PHB beads and Pseudomonas fluorescens (PFL) immobilized on large PHB beads. The latter preparation presented the highest productivity (40.9 mg of ethyl esters mg(-1) immobilized protein h(-1)).

Enzyme immobilization by adsorption: a review

“…These properties can also be adapted by preparing the polymer composites. The synthetic polymers most commonly used as enzyme carriers include: poly(vinyl alcohol) (PVA) (Mendes et al 2012) (commercial product LentiKats) (Kubac et al 2006); crosslinked poly(vinyl alcohol) (Ozturk and Kilinc 2010); poly(N-methylolacrylamide) (Santos et al 2007); polypropylene (commercial products Accurel EP100 (Torres et al 2008) and Accurel MP1000 (Hita et al 2009); polystyrene in the form of foam (Akdogan and Pazarlioglu 2011), in which immobilization is facilitated by a large number of pores; and poly(acrylic acid-co-acrylamide)/ hydrotalcite nanocomposite hydrogels (Zhang et al 2009). An interesting enzyme carrier is the biodegradable and thermo-shrinkable hydroxybutyrate.…”

“…These give rise to the interactions sufficiently strong for the enzyme-carrier binding (adsorption) to occur (Kosaka et al 2007;Gustafsson et al 2012;Wu et al 2012). When such groups are absent, the carrier is subjected to a chemical modification (Cho et al 2012;Mendes et al 2012;Zaidan et al 2012). The modifying agent should have at least two reactive groups in its molecule; one should enable it to chemically anchor on the carrier and the other one, to physically interact with the enzyme.…”

“…Organic carriers seem to be preferred for the immobilization of lipases. They include a wide and highly diverse gamut of polymers, such as cross-linked PVA (Ozturk and Kilinc 2010) and epoxy activated PVA (Mendes et al, 2012), poly(N-methylol acrylamide) (Santos et al 2007), small and large poly(hydroxybutyrate) beads (Mendes et al 2011) and polyacrylonitryle electrospun fibres (Sakai et al 2010), organic matrices of natural origin, including chitosan beads (Nasratun et al 2010), MANAE-agarose and cellulose ultrathin film (Kosaka et al 2007), commercial polymer products, e.g. polypropylene (c) Fig.…”

Combi-protein coated microcrystals of lipases for production of biodiesel from oil from spent coffee grounds

“…When an enzyme is used as a catalyst, the reaction can be carried out at a moderate temperature; downstream processing is easier and if the feedstock oil contains high FFA content, enzymatic process seems to be more robust to deal with it [19][20][21][22][23][24][25]. Lipases have been used for this purpose and the process has been described with a very large number of oils and fats with varying degree of success [39][40][41][42][43][44][45][46].…”

Immobilisation of endoinulinase on polyhydroxybutyrate microfibers

“…Among PHAs, polyhydroxybutyrate (PHB) is a short-chain-length polymer synthesised by bacteria and it is the most frequently studied among the PHA polymers (Deepak et al 2009). PHB particles or beads have already been used for immobilisation of nattokinase (Deepak et al 2009) and lipases (Mendes et al 2012;Silva et al 2014).…”